文章以北京市传统中轴线及向北延伸至北四环的区域为研究范围,选用2017年7月中旬沿线不同等级街道的街景图像,运用Adobe Photoshop CC 2018、ImageJ和SPSS 20.对街道系统绿视率进行统计计算和辅助分析。研究结果发现:北京市中轴线绿视...文章以北京市传统中轴线及向北延伸至北四环的区域为研究范围,选用2017年7月中旬沿线不同等级街道的街景图像,运用Adobe Photoshop CC 2018、ImageJ和SPSS 20.对街道系统绿视率进行统计计算和辅助分析。研究结果发现:北京市中轴线绿视率整体呈现一般的绿化水平,各街道(及广场)绿化评价占比情况为绿化水平一般>较好>差>高>较差;中轴线绿化重视程度北部大于南部;街道等级和街道剖面结构不是影响绿视率的主要因素,绿化带宽度、绿色景观连续性及植被养护状况等植被因素的综合考虑是提高绿视率的有效方案;中轴线的绿化建设应当提高对天安门广场、商业步行街和南部二级道路的重视程度,同时加强植被的养护管理。展开更多
Quick and reliable identification of the traffic state is of critical importance to traffic control systems, especially when spillovers appear. Firstly, a calculation method for the occupancy per cycle under different...Quick and reliable identification of the traffic state is of critical importance to traffic control systems, especially when spillovers appear. Firstly, a calculation method for the occupancy per cycle under different traffic conditions were presented, based on the relationship between the three basic traffic flow parameters, speed, traffic flow and density. Secondly, the times at which the stopping and starting waves approach a loop detector were confirmed using the traffic wave models modified by a kinematic equation. Then, the threshold of occupancy, which characterizes the appearance of spillovers, was determined by the premise that the stopping and starting waves had the same speed. At last, the accuracy and usability of the new method were verified by VISSIM simulation, using the ratio of misjudgment as the evaluation index. The results show that the ratio of misjudgment of the new method is about 11.36% compared to 17.65% of the previous method.展开更多
文摘文章以北京市传统中轴线及向北延伸至北四环的区域为研究范围,选用2017年7月中旬沿线不同等级街道的街景图像,运用Adobe Photoshop CC 2018、ImageJ和SPSS 20.对街道系统绿视率进行统计计算和辅助分析。研究结果发现:北京市中轴线绿视率整体呈现一般的绿化水平,各街道(及广场)绿化评价占比情况为绿化水平一般>较好>差>高>较差;中轴线绿化重视程度北部大于南部;街道等级和街道剖面结构不是影响绿视率的主要因素,绿化带宽度、绿色景观连续性及植被养护状况等植被因素的综合考虑是提高绿视率的有效方案;中轴线的绿化建设应当提高对天安门广场、商业步行街和南部二级道路的重视程度,同时加强植被的养护管理。
基金Project(2011AA110304) supported by the National High Technology Research and Development Program of China
文摘Quick and reliable identification of the traffic state is of critical importance to traffic control systems, especially when spillovers appear. Firstly, a calculation method for the occupancy per cycle under different traffic conditions were presented, based on the relationship between the three basic traffic flow parameters, speed, traffic flow and density. Secondly, the times at which the stopping and starting waves approach a loop detector were confirmed using the traffic wave models modified by a kinematic equation. Then, the threshold of occupancy, which characterizes the appearance of spillovers, was determined by the premise that the stopping and starting waves had the same speed. At last, the accuracy and usability of the new method were verified by VISSIM simulation, using the ratio of misjudgment as the evaluation index. The results show that the ratio of misjudgment of the new method is about 11.36% compared to 17.65% of the previous method.
